The abandoned ruins of this unfinished missile defense radar site dominate the Montana prairie. SAFEGUARD was the predecessor to the ill-fated Star Wars program of the Reagan era, and the current missile defense system being deployed in Alaska and California. The Montana site was ten-percent complete when construction was halted by the signing of the SALT 1 ABM Treaty in 1972. Its sister site in North Dakota was deactivated in 1975 after only four months of operation. The total cost for development and construction of SAFEGUARD was more than twenty-five billion dollars (in current adjusted dollars), approximately one-fourth the cost of the Apollo moon-landing program.